Oilfield operators seek to maximize hydrocarbon recovery within a given budget and timeframe. While they perform as much logging and surveying as feasible before and during the drilling and completion of production and, in some cases, injection wells, the information gathering process does not end there. The operators also wish to track the movement of fluids in and around the reservoirs, as this information enables them to adjust the distribution and rates of production among the producing and/or injection wells to avoid premature water breakthroughs and other obstacles to efficient and profitable operation. Moreover, such information gathering further enables the operators to better evaluate treatment and secondary recovery strategies for enhanced hydrocarbon recoveries.
Electromagnetic tomography offers one approach for mapping and monitoring fluid distributions between and around boreholes containing arrays of electromagnetic field transmitters and sensors. Yet the usefulness of electromagnetic tomography suffers due to a lack of sensitive, cost-effective sensing array designs suitable for deployment in hostile downhole conditions.
It should be understood, however, that the specific embodiments given in the drawings and detailed description do not limit the disclosure. On the contrary, they provide the foundation for one of ordinary skill to discern the alternative forms, equivalents, and modifications that are encompassed together with one or more of the given embodiments in the scope of the appended claims.